glibc/nis/nss_nis/nis-service.c

/* Copyright (C) 1996-2004, 2006 Free Software Foundation, Inc.
   This file is part of the GNU C Library.
   Contributed by Thorsten Kukuk <kukuk@suse.de>, 1996.

   The GNU C Library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public
   License as published by the Free Software Foundation; either
   version 2.1 of the License, or (at your option) any later version.

   The GNU C Library is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public
   License along with the GNU C Library; if not, write to the Free
   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
   02111-1307 USA.  */

#include <nss.h>
#include <netdb.h>
#include <ctype.h>
#include <errno.h>
#include <string.h>
#include <bits/libc-lock.h>
#include <rpcsvc/yp.h>
#include <rpcsvc/ypclnt.h>

#include "nss-nis.h"
#include <libnsl.h>


/* Get the declaration of the parser function.  */
#define ENTNAME servent
#define EXTERN_PARSER
#include <nss/nss_files/files-parse.c>

__libc_lock_define_initialized (static, lock)

struct response_t
{
  struct response_t *next;
  size_t size;
  char mem[0];
};

typedef struct intern_t
{
  struct response_t *start;
  struct response_t *next;
  size_t offset;
} intern_t;

static intern_t intern;

struct search_t
{
  const char *name;
  const char *proto;
  int port;
  enum nss_status status;
  struct servent *serv;
  char *buffer;
  size_t buflen;
  int *errnop;
};

static int
saveit (int instatus, char *inkey, int inkeylen, char *inval,
        int invallen, char *indata)
{
  if (instatus != YP_TRUE)
    return 1;

  if (inkey && inkeylen > 0 && inval && invallen > 0)
    {
      struct response_t *bucket = intern.next;

      if (__builtin_expect (bucket == NULL, 0))
	{
#define MINSIZE 4096 - 4 * sizeof (void *)
	  const size_t minsize = MAX (MINSIZE, 2 * (invallen + 1));
	  bucket = malloc (sizeof (struct response_t) + minsize);
	  if (bucket == NULL)
	    /* We have no error code for out of memory.  */
	    return 1;

	  bucket->next = NULL;
	  bucket->size = minsize;
	  intern.start = intern.next = bucket;
	  intern.offset = 0;
	}
      else if (__builtin_expect (invallen + 1 > bucket->size - intern.offset,
				 0))
	{
	  /* We need a new (larger) buffer.  */
	  const size_t newsize = 2 * MAX (bucket->size, invallen + 1);
	  struct response_t *newp = malloc (sizeof (struct response_t)
					    + newsize);
	  if (newp == NULL)
	    /* We have no error code for out of memory.  */
	    return 1;

	  /* Mark the old bucket as full.  */
	  bucket->size = intern.offset;

	  newp->next = NULL;
	  newp->size = newsize;
	  bucket = intern.next = bucket->next = newp;
	  intern.offset = 0;
	}

      char *p = mempcpy (&bucket->mem[intern.offset], inval, invallen);
      if (__builtin_expect (p[-1] != '\0', 0))
	{
	  *p = '\0';
	  ++invallen;
	}
      intern.offset += invallen;
    }

  return 0;
}

static int
dosearch (int instatus, char *inkey, int inkeylen, char *inval,
	  int invallen, char *indata)
{
  struct search_t *req = (struct search_t *) indata;

  if (__builtin_expect (instatus != YP_TRUE, 0))
    return 1;

  if (inkey && inkeylen > 0 && inval && invallen > 0)
    {
      if (__builtin_expect ((size_t) (invallen + 1) > req->buflen, 0))
	{
	  *req->errnop = ERANGE;
	  req->status = NSS_STATUS_TRYAGAIN;
	  return 1;
	}

      char *p = strncpy (req->buffer, inval, invallen);
      req->buffer[invallen] = '\0';
      while (isspace (*p))
        ++p;

      int parse_res = _nss_files_parse_servent (p, req->serv,
						(void *) req->buffer,
						req->buflen, req->errnop);
      if (parse_res == -1)
	{
	  req->status = NSS_STATUS_TRYAGAIN;
	  return 1;
	}

      if (!parse_res)
        return 0;

      if (req->proto != NULL && strcmp (req->serv->s_proto, req->proto) != 0)
	return 0;

      if (req->port != -1 && req->serv->s_port != req->port)
	return 0;

      if (req->name != NULL && strcmp (req->serv->s_name, req->name) != 0)
	{
	  char **cp;
	  for (cp = req->serv->s_aliases; *cp; cp++)
	    if (strcmp (req->name, *cp) == 0)
	      break;

	  if (*cp == NULL)
	    return 0;
	}

      req->status = NSS_STATUS_SUCCESS;
      return 1;
    }

  return 0;
}

static void
internal_nis_endservent (void)
{
  struct response_t *curr = intern.next;

  while (curr != NULL)
    {
      struct response_t *last = curr;
      curr = curr->next;
      free (last);
    }

  intern.next = intern.start = NULL;
}

enum nss_status
_nss_nis_endservent (void)
{
  __libc_lock_lock (lock);

  internal_nis_endservent ();

  __libc_lock_unlock (lock);

  return NSS_STATUS_SUCCESS;
}

static enum nss_status
internal_nis_setservent (void)
{
  char *domainname;
  struct ypall_callback ypcb;
  enum nss_status status;

  if (yp_get_default_domain (&domainname))
    return NSS_STATUS_UNAVAIL;

  internal_nis_endservent ();

  ypcb.foreach = saveit;
  ypcb.data = NULL;
  status = yperr2nss (yp_all (domainname, "services.byname", &ypcb));

  /* Mark the last buffer as full.  */
  if (intern.next != NULL)
    intern.next->size = intern.offset;

  intern.next = intern.start;
  intern.offset = 0;

  return status;
}

enum nss_status
_nss_nis_setservent (int stayopen)
{
  enum nss_status status;

  __libc_lock_lock (lock);

  status = internal_nis_setservent ();

  __libc_lock_unlock (lock);

  return status;
}

static enum nss_status
internal_nis_getservent_r (struct servent *serv, char *buffer,
			   size_t buflen, int *errnop)
{
  struct parser_data *pdata = (void *) buffer;
  int parse_res;
  char *p;

  if (intern.start == NULL)
    internal_nis_setservent ();

  /* Get the next entry until we found a correct one.  */
  do
    {
      struct response_t *bucket = intern.next;

      if (__builtin_expect (intern.offset >= bucket->size, 0))
	{
	  if (bucket->next == NULL)
	    return NSS_STATUS_NOTFOUND;

	  /* We look at all the content in the current bucket.  Go on
	     to the next.  */
	  bucket = intern.next = bucket->next;
	  intern.offset = 0;
	}

      for (p = &bucket->mem[intern.offset]; isspace (*p); ++p)
        ++intern.offset;

      size_t len = strlen (p) + 1;
      if (__builtin_expect (len > buflen, 0))
	{
	  *errnop = ERANGE;
	  return NSS_STATUS_TRYAGAIN;
	}

      /* We unfortunately have to copy the data in the user-provided
	 buffer because that buffer might be around for a very long
	 time and the servent structure must remain valid.  If we would
	 rely on the BUCKET memory the next 'setservent' or 'endservent'
	 call would destroy it.

	 The important thing is that it is a single NUL-terminated
	 string.  This is what the parsing routine expects.  */
      p = memcpy (buffer, &bucket->mem[intern.offset], len);

      parse_res = _nss_files_parse_servent (p, serv, pdata, buflen, errnop);
      if (__builtin_expect (parse_res == -1, 0))
        return NSS_STATUS_TRYAGAIN;

      intern.offset += len;
    }
  while (!parse_res);

  return NSS_STATUS_SUCCESS;
}

enum nss_status
_nss_nis_getservent_r (struct servent *serv, char *buffer, size_t buflen,
		       int *errnop)
{
  enum nss_status status;

  __libc_lock_lock (lock);

  status = internal_nis_getservent_r (serv, buffer, buflen, errnop);

  __libc_lock_unlock (lock);

  return status;
}

enum nss_status
_nss_nis_getservbyname_r (const char *name, const char *protocol,
			  struct servent *serv, char *buffer, size_t buflen,
			  int *errnop)
{
  if (name == NULL)
    {
      *errnop = EINVAL;
      return NSS_STATUS_UNAVAIL;
    }

  char *domain;
  if (__builtin_expect (yp_get_default_domain (&domain), 0))
    return NSS_STATUS_UNAVAIL;

  /* If the protocol is given, we could try if our NIS server knows
     about services.byservicename map. If yes, we only need one query.  */
  size_t keylen = strlen (name) + 1 + (protocol ? strlen (protocol) : 0);
  char key[keylen + 1];

  /* key is: "name/proto" */
  char *cp = stpcpy (key, name);
  if (protocol != NULL)
    {
      *cp++ = '/';
      strcpy (cp, protocol);
    }

  char *result;
  int int_len;
  enum nss_status status = yperr2nss (yp_match (domain,
						"services.byservicename", key,
						keylen, &result, &int_len));
  size_t len = int_len;

  /* If we found the key, it's ok and parse the result. If not,
     fall through and parse the complete table. */
  if (__builtin_expect (status == NSS_STATUS_SUCCESS, 1))
    {
      if (__builtin_expect ((size_t) (len + 1) > buflen, 0))
	{
	  free (result);
	  *errnop = ERANGE;
	  return NSS_STATUS_TRYAGAIN;
	}

      char *p = strncpy (buffer, result, len);
      buffer[len] = '\0';
      while (isspace (*p))
	++p;
      free (result);

      int parse_res = _nss_files_parse_servent (p, serv, (void *) buffer,
						buflen, errnop);
      if (__builtin_expect (parse_res < 0, 0))
	{
	  if (parse_res == -1)
	    return NSS_STATUS_TRYAGAIN;
	  else
	    return NSS_STATUS_NOTFOUND;
	}
      else
	return NSS_STATUS_SUCCESS;
    }

  /* Check if it is safe to rely on services.byservicename.  */
  if (_nsl_default_nss () & NSS_FLAG_SERVICES_AUTHORITATIVE)
    return status;

  struct ypall_callback ypcb;
  struct search_t req;

  ypcb.foreach = dosearch;
  ypcb.data = (char *) &req;
  req.name = name;
  req.proto = protocol;
  req.port = -1;
  req.serv = serv;
  req.buffer = buffer;
  req.buflen = buflen;
  req.errnop = errnop;
  req.status = NSS_STATUS_NOTFOUND;
  status = yperr2nss (yp_all (domain, "services.byname", &ypcb));

  if (status != NSS_STATUS_SUCCESS)
    return status;

  return req.status;
}

enum nss_status
_nss_nis_getservbyport_r (int port, const char *protocol,
			  struct servent *serv, char *buffer,
			  size_t buflen, int *errnop)
{
  char *domain;
  if (__builtin_expect (yp_get_default_domain (&domain), 0))
    return NSS_STATUS_UNAVAIL;

  /* If the protocol is given, we only need one query.
     Otherwise try first port/tcp, then port/udp and then fallback
     to sequential scanning of services.byname.  */
  const char *proto = protocol != NULL ? protocol : "tcp";
  do
    {
      /* key is: "port/proto" */
      char key[sizeof (int) * 3 + strlen (proto) + 2];
      size_t keylen = snprintf (key, sizeof (key), "%d/%s", ntohs (port),
				proto);

      char *result;
      int int_len;
      enum nss_status status = yperr2nss (yp_match (domain, "services.byname",
						    key, keylen, &result,
						    &int_len));
      size_t len = int_len;

      /* If we found the key, it's ok and parse the result. If not,
	 fall through and parse the complete table. */
      if (status == NSS_STATUS_SUCCESS)
	{
	  if (__builtin_expect ((size_t) (len + 1) > buflen, 0))
	    {
	      free (result);
	      *errnop = ERANGE;
	      return NSS_STATUS_TRYAGAIN;
	    }

	  char  *p = strncpy (buffer, result, len);
	  buffer[len] = '\0';
	  while (isspace (*p))
	    ++p;
	  free (result);
	  int parse_res = _nss_files_parse_servent (p, serv, (void *) buffer,
						    buflen, errnop);
	  if (__builtin_expect (parse_res < 0, 0))
	    {
	      if (parse_res == -1)
		return NSS_STATUS_TRYAGAIN;
	      else
		return NSS_STATUS_NOTFOUND;
	    }

	  return NSS_STATUS_SUCCESS;
	}
    }
  while (protocol == NULL && (proto[0] == 't' ? (proto = "udp") : NULL));

  if (port == -1)
    return NSS_STATUS_NOTFOUND;

  struct ypall_callback ypcb;
  struct search_t req;

  ypcb.foreach = dosearch;
  ypcb.data = (char *) &req;
  req.name = NULL;
  req.proto = protocol;
  req.port = port;
  req.serv = serv;
  req.buffer = buffer;
  req.buflen = buflen;
  req.errnop = errnop;
  req.status = NSS_STATUS_NOTFOUND;
  enum nss_status status = yperr2nss (yp_all (domain, "services.byname",
					      &ypcb));

  if (status != NSS_STATUS_SUCCESS)
    return status;

  return req.status;
}